Corrugated or convoluted tubular members made of a relatively high modulus plastic material are commonly used, for example, as sleeving in the automotive industry. Typically, relatively stiff materials are chosen for the sleeving to provide abrasion resistance for the components being protected. Such materials are usually employed for the additional reason that their durability gives protection over long periods of time, desirably over the life of a vehicle in which the tubular members are utilized. In the selection of such tubing, a preferred form is fabricated with a convoluted or corrugated wall profile, wherein the corrugations or convolutions extend substantially circumferentially so as to impart to the product a flexibility which allows it to follow a path which may include one or more relatively sharp bends without collapsing at the bend points.
In the installation over hoses, pipes or wires in a typical engine compartment, the components being protected are often previously installed, and the protective tubing is longitudinally slit so that the edges of the slit can be separated manually by a worker and the tubing is thus slipped over the articles in need of protection. The slit is then allowed to close and tape is applied so that the tubing does not fall off the article being protected.
Various problems exist in the installation and use of the protective tubing just described. In the first place, manual separation of the slit edges by the worker tends to cause injury to the fingers owing to the relatively sharp edges of the slit when using the relatively stiff materials preferred for the purposes of imparting durability and abrasion resistance to the product. Second, taping to insure against opening of the slit is a labor-intensive step which is undesirably expensive. Finally, during use of the vehicle, bending and twisting forces occur, particularly when the vehicle is moving over relatively rough surfaces create undesirable noises due to the edges of the slit rubbing against one another. These forces may even open the slit sufficiently to allow small articles, such as wires, to be pinched and even severed.